Rail-bond.



F. H. DANIELS & G. R. STURDEVANT.

RAIL BOND.

APPLICATION FILED DE(].1I 1900.

900,488. Patented Oct. 6, 1908. I

SSES INVENTORS 'a/mrn m UNITED STATES PATENT OFFICE.

FRED H. DANIELS AND CHARLES R. STURDEVANT, OF WORCESTER, MASSACHUSETTS, ASSIGNORS TO AMERICAN STEEL & WIRE COMPANY, OF CHICAGO, ILLINOIS, ACOR- PORATION OF NEW JERSEY.

BAIL-Bonn.

Patented Oct. 6,1908.

Application filed December .1, 1966. Serial No. 345,899.

To all whom 'it may concern:

Be it known that we, FRED H. DANIELS, of Worcester, Worcester county, Massa-' provement in Rail-Bonds, of which the fol- 1 proved structure and arrangement of the.

owing is a full, clear, and exact description,

reference being had to the accompanyingdrawings, forming part of this specification,-

Figure 1 is a perspective view showing the' ends of rails provided with our im roved bond; Fig. 2 1s a cross-section of t e rail showing the stud in dotted lines; and Figs. 3 and 4 are cross-sections of rails showing modified forms and arrangements of the bond.

Our invention relates to the class of rail bonds, and isdesigned to provide an imond which will provide for increased contact pressure, increased area of contact, and anchoring of the stud in position.

In the drawings, referring to the form of Figs. 1 and 2, 2, 2 represent the copper heads of the bond connected by the conductin cables 3. Each head is shown as provided with two studs 4 of copper or suitable conducting material, such studs bein provided with a cavity extending inwar y for the major pprtion'of the length of the stud and refera ly nearly its entire length. The

ottomed holes in the heads of the rails are formed of a suitable size to neatly receive the studs.

After the studs are ositioned in the-holes, a steel expanding too or pin is driven into the cavity in each stud, thus forc' the co per against the-wall and bottom c? the ho e and obtaining intimate contact. As the cavity in the rail is bottomed, it prevents the flow of copper in one direction when the pin is driven into the. terminal, thus giving a very intense contact ressure. B dr' or otherwise forming t 6 hole to wit about a sixteenth ofan inch to the bottom of the stud and not entirely through it, we also gain in the amount of contact area in tubular stud work. We also referablythread, score or enlarge the wall 0? the hole in the rail in the rear of the outlet, so that the stud will be anchored and the contact area and contact pressure increased. Thus, in Fig. 3, we

show the bottomed holes as formed'in the hole and fiOVidt-Bd with a closed'bottom an .cess in the wall of the hole, a terminal stud base 6 of the rail with a groove 7 cut in the wall of the hole back of its entrance. Otherwise, the stud and bond construction is substantially the same as in the form of Figs. 1 an}?l 2, 4? being the stud and 3 the flexible ca e.

In 4' we show a form similar to that of.

Fig. 3, except that the hole'for the stud is flared inwardly, bein of gradually increasing' diameter from t e entrance. In this case 6 is the base of the rail, 4 the stud,

and 3 the connecting cable.

In all the forms, we may employ one of any number of studs for each terminal of the bond, thus increasing the contact area to any desired amount, each being independent of the others electrically.

The advantages of our invention result from the use of the bottomed cavity in the stud in connection with the bottomed hole in the rail. 1 The bottom of the hole in the rail prevents the flow; of copper in one direction, and enables us to obtaln'a greater contact pressure than with studs havmli a hole completely through them. By dri 'ng or otherwise forming the hole in the stud so as to leave a bottom formed by the end portion of the stud, we obtain an increase in contact area equal tothe area of this end portion. By threading or enlarging the wall of the hole in the rail back of the entrance, the 'stud is not only anchored d the contact area increased, but the contact pressure may also be increased, since the portlons having the enlarged area tend to prevent backward flow of the metal so that an increased pressure ma be obtained.

0 bottomed hole may be formed in any desired part of the rail, the number and form.

of the studs-may be varied, and other variations may be made without departing from .our invention.

1. s A rail having a hole with a closed bottom, a terminal stud ex anded within the ongitudinal recess opening ough the outer end of the stud and terminating short of the opposite end thereof, and an expanding in driven into the recess, the bottomwall 0 0 hole protecting the stud and also forming an anvil or backing therefor. 1 a

2. A rail ha a hole rovided with a an; an argrooveor reexpanded within the groove of the hole and In testimony whereof, We have hereunto provided with a longitudinal recess opening set our hands.

through the outer end of the stud and termi- FRED H. DANIELS.

nating short of the inner end thereof, and an CHARLES R. STURDEVANT. expanding in driven into the recess, the bot: Witnesses:

tom wall 0 the hole rotecting the stud and WM. A. BACON,

also forming an anvii or backing therefor. A. F. BAOKLIN. 

